Etching is widely used in the fabrication of integrated chips. Etching is a process by which material is removed from a semiconductor substrate to provide a topology that is used to form one or more layers on the semiconductor substrate. For example, to form a metal interconnect layer, a dielectric material may be formed over a semiconductor substrate and be selectively etched to form a trench in which a metal is subsequently deposited.
Typically, etching is performed by selectively exposing a surface of a semiconductor substrate to an etchant, which removes material from the surface of the semiconductor substrate. The etchant may comprise particles that react with an exposed surface of the semiconductor substrate. For example, a dry etchant may comprise energized particles which collide with an exposed surface of a semiconductor substrate to dislodge atoms from the exposed surface.